The proposed study responds to PA-09-236 entitled HIV/AIDS, Drug Use, and Vulnerable Populations. This study is a randomized controlled trial (RCT) that will rigorously evaluate the implementation, effectiveness and cost-effectiveness of a couple-based integrated HIV/STI and drug abuse prevention intervention (Connect II) with drug-involved male offenders charged with misdemeanors and their primary female sexual partners, implemented by frontline providers in Criminal Court, Community Court or Probation (CCP) sites in the Bronx, NY, compared to CCP standard treatment of care services (TAU). The primary outcomes are biologically confirmed sexually transmitted infections (STIs) and self-reported condom use. This study will yield important data on implementation factors associated with effectiveness of the proposed intervention in real world resource-constrained criminal justice settings. The proposed CCP study sites are located in the South Bronx, the poorest Congressional District in the U.S. with 96% of residents identifying as Black or Latino. The South Bronx has an HIV prevalence rate of 2.6%. Research has found that 12% of men on probation in New York City are HIV positive. Though the criminal justice system is recognized as the epicenter of the epidemic in the U.S., few, if any, HIV prevention interventions have been developed for the huge number of male offenders under community supervision who represent 90% of the corrections population. No HIV/STI prevention services are currently provided at the proposed CCP sites. The proposed intervention is designed to address this critical gap in services. Connect II was found to be efficacious among drug-involved couples in reducing risky drug and sexual behaviors and drug use. In the proposed study we aim to advance the knowledge of implementation science by testing the effectiveness and cost-effectiveness of Connect II delivered by frontline providers in the real world settings of CCP sites with 240 drug-involved male offenders and their female partners (N=480 participants). Eligible couples will be randomly assigned to either (1) a 4-session Connect II delivered to both partners together + TAU delivered to male participant alone, or (2) a TAU control condition delivered to the male participant. Repeated assessments will occur at baseline and 3, 6, and 12-months post intervention. The study will be conducted by Dr. Nabila El-Bassel, Dr. Louisa Gilbert, and an investigative team from Columbia University in collaboration with Michael Rempel from the Center for Court Innovation and the New York City Department of Probation. If found to be effective, Connect II may be scaled up in community criminal justice settings nationwide to curb the spread of HIV/STIs and to reduce HIV disparities in heavily impacted communities like the South Bronx. PUBLIC HEALTH RELEVANCE: This study addresses the significant public health threat of HIV and other STIs among drug- involved male offenders under community supervision and their female partners. This study will evaluate the implementation, effectiveness and cost-effectiveness of a brief couple-based HIV and drug abuse prevention intervention for drug-involved male offenders and their female partners delivered by frontline providers in Criminal/Community Court and Probation sites in the South Bronx, the poorest congressional district in the U.S. If found to be effective, the proposed brief intervention may be scaled up to community criminal justice sites nationwide to curb the spread of HIV/STIs and reduce HIV disparities.